Boards by deck size
How many deck boards for common deck sizes
Board counts for popular deck sizes, worked out with the same engine as the deck board calculator: 5-1/2" boards, a 1/8" (wood) or 3/16" (composite) gap, joists at 16" on center and 10% extra. Pick a size for the full breakdown.
| Deck size | Area | Pressure-treated (buy) | Composite (buy) | Linear ft (composite) |
|---|---|---|---|---|
| 8×8 deck | 64 sq ft | 20 × 8-ft (20) | 10 × 20-ft (10) | 200 |
| 8×10 deck | 80 sq ft | 20 × 10-ft (20) | 19 × 12-ft (19) | 228 |
| 10×10 deck | 100 sq ft | 25 × 10-ft (25) | 25 × 12-ft (25) | 300 |
| 10×12 deck | 120 sq ft | 29 × 10-ft (29) | 25 × 12-ft (25) | 300 |
| 10×16 deck | 160 sq ft | 39 × 10-ft (39) | 25 × 16-ft (25) | 400 |
| 12×12 deck | 144 sq ft | 29 × 12-ft (29) | 29 × 12-ft (29) | 348 |
| 12×16 deck | 192 sq ft | 29 × 16-ft (29) | 38 × 12-ft (38) | 456 |
| 12×20 deck | 240 sq ft | 48 × 12-ft (48) | 48 × 12-ft (48) | 576 |
| 12×24 deck | 288 sq ft | 58 × 12-ft (58) | 57 × 12-ft (57) | 684 |
| 14×14 deck | 196 sq ft | 33 × 16-ft (33) | 33 × 16-ft (33) | 528 |
| 14×20 deck | 280 sq ft | 36 × 12-ft + 30 × 8-ft (66) | 33 × 20-ft (33) | 660 |
| 16×16 deck | 256 sq ft | 39 × 16-ft (39) | 38 × 16-ft (38) | 608 |
| 16×20 deck | 320 sq ft | 48 × 16-ft (48) | 38 × 20-ft (38) | 760 |
| 20×20 deck | 400 sq ft | 52 × 12-ft + 43 × 8-ft (95) | 48 × 20-ft (48) | 960 |
Your deck isn't listed or uses different boards? The deck board calculator handles any size, L-shapes, picture frames and metric.
Deck size questions
What is the most popular deck size?
There's no official figure for the most common deck size, but sizes like 12×12, 12×16 and 16×20 ft turn up again and again in plans. They match standard 12-, 16- and 20-ft board and joist lengths, so they waste little material. The best size for you depends on how you'll use the deck and the space you have.
What size deck should I build?
Start from what you want on it. A dining table for four with chairs pulled out needs a zone of roughly 10 × 10 ft (a 48" table plus about 3 ft on each side), a small lounge group needs a similar area, and a grill needs its own space with the clearance its manual specifies. Add up the zones you want, allow walkways between them, and keep the deck in proportion to the house. Then pick dimensions that suit stock board lengths — the table above shows how each size works out.
What is the perfect deck size?
The one that fits how you'll use it without crowding the yard. As a rough guide, 8×8 to 10×10 ft suits a bistro set or a landing, 12×12 to 12×16 ft fits a dining table or a seating group, and 16×20 ft and up has room for dining, lounging and a grill together. Mark the outline on the ground with stakes before you decide — it's the quickest way to see whether a size feels right.
How many square feet are common deck sizes?
Multiply the two sides: a 10×10 deck is 100 sq ft, a 12×12 is 144 sq ft, a 12×16 is 192 sq ft, a 16×20 is 320 sq ft and a 20×20 is 400 sq ft. The table above lists every size, and the square footage calculator handles L-shapes and other outlines.
Why do some deck sizes waste more boards?
Boards come in fixed lengths, usually 8 to 16 ft for wood and 12, 16 and 20 ft for composite. A 16-ft run uses 16-ft boards with no offcut, but a 17-ft run needs a seam in every row and leaves offcuts you may not reuse. Choosing a deck length that matches a stock board length is the easiest way to save material.